[builtins] Port Number.prototype.toString to Torque

Bug: v8:7864
Change-Id: Iaeca4ab9d098edc73b2191dc260dd37a6114f3bc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1893732
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64760}

AUTHORS

@@ -196,6 +196,7 @@ Wiktor Garbacz <wiktor.garbacz@gmail.com>
 Xiaoyin Liu <xiaoyin.l@outlook.com>
 Yannic Bonenberger <contact@yannic-bonenberger.com>
 Yong Wang <ccyongwang@tencent.com>
+Youfeng Hao <ajihyf@gmail.com>
 Yu Yin <xwafish@gmail.com>
 Zac Hansen <xaxxon@gmail.com>
 Zhao Jiazhong <kyslie3100@gmail.com>

BUILD.gn

@@ -952,6 +952,7 @@ torque_files = [
   "src/builtins/internal-coverage.tq",
   "src/builtins/iterator.tq",
   "src/builtins/math.tq",
+  "src/builtins/number.tq",
   "src/builtins/object-fromentries.tq",
   "src/builtins/object.tq",
   "src/builtins/promise-abstract-operations.tq",

src/builtins/base.tq

@@ -1469,6 +1469,8 @@ const kBoolean: constexpr PrimitiveType
     generates 'PrimitiveType::kBoolean';
 const kSymbol: constexpr PrimitiveType
     generates 'PrimitiveType::kSymbol';
+const kNumber: constexpr PrimitiveType
+    generates 'PrimitiveType::kNumber';
 
 const kNameDictionaryInitialCapacity:
     constexpr int32 generates 'NameDictionary::kInitialCapacity';

src/builtins/builtins-definitions.h

@@ -670,7 +670,6 @@ namespace internal {
   CPP(NumberPrototypeToFixed)                                                  \
   CPP(NumberPrototypeToLocaleString)                                           \
   CPP(NumberPrototypeToPrecision)                                              \
-  CPP(NumberPrototypeToString)                                                 \
   /* ES6 #sec-number.prototype.valueof */                                      \
   TFJ(NumberPrototypeValueOf, 0, kReceiver)                                    \
   TFC(Add, BinaryOp)                                                           \

src/builtins/builtins-number.cc

@@ -186,65 +186,5 @@ BUILTIN(NumberPrototypeToPrecision) {
   return *result;
 }
 
-// ES6 section 20.1.3.6 Number.prototype.toString ( [ radix ] )
-BUILTIN(NumberPrototypeToString) {
-  HandleScope scope(isolate);
-  Handle<Object> value = args.at(0);
-  Handle<Object> radix = args.atOrUndefined(isolate, 1);
-
-  // Unwrap the receiver {value}.
-  if (value->IsJSPrimitiveWrapper()) {
-    value = handle(Handle<JSPrimitiveWrapper>::cast(value)->value(), isolate);
-  }
-  if (!value->IsNumber()) {
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewTypeError(MessageTemplate::kNotGeneric,
-                              isolate->factory()->NewStringFromAsciiChecked(
-                                  "Number.prototype.toString"),
-                              isolate->factory()->Number_string()));
-  }
-  double const value_number = value->Number();
-
-  // If no {radix} was specified, just return ToString of {value}.
-  if (radix->IsUndefined(isolate)) {
-    return *isolate->factory()->NumberToString(value);
-  }
-
-  // Convert the {radix} to an integer first.
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, radix,
-                                     Object::ToInteger(isolate, radix));
-  double const radix_number = radix->Number();
-
-  // If {radix} is 10, just return ToString of {value}.
-  if (radix_number == 10.0) return *isolate->factory()->NumberToString(value);
-
-  // Make sure the {radix} is within the valid range.
-  if (radix_number < 2.0 || radix_number > 36.0) {
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewRangeError(MessageTemplate::kToRadixFormatRange));
-  }
-
-  // Fast case where the result is a one character string.
-  if ((IsUint32Double(value_number) && value_number < radix_number) ||
-      IsMinusZero(value_number)) {
-    // Character array used for conversion.
-    static const char kCharTable[] = "0123456789abcdefghijklmnopqrstuvwxyz";
-    return *isolate->factory()->LookupSingleCharacterStringFromCode(
-        kCharTable[static_cast<uint32_t>(value_number)]);
-  }
-
-  // Slow case.
-  if (std::isnan(value_number)) return ReadOnlyRoots(isolate).NaN_string();
-  if (std::isinf(value_number)) {
-    return (value_number < 0.0) ? ReadOnlyRoots(isolate).minus_Infinity_string()
-                                : ReadOnlyRoots(isolate).Infinity_string();
-  }
-  char* const str =
-      DoubleToRadixCString(value_number, static_cast<int>(radix_number));
-  Handle<String> result = isolate->factory()->NewStringFromAsciiChecked(str);
-  DeleteArray(str);
-  return *result;
-}
-
 }  // namespace internal
 }  // namespace v8

src/builtins/number.tq

@@ -0,0 +1,79 @@
+// Copyright 2019 the V8 project authors. All rights reserved. Use of this
+// source code is governed by a BSD-style license that can be found in the
+// LICENSE file.
+
+namespace runtime {
+  extern transitioning runtime
+  DoubleToStringWithRadix(implicit context: Context)(Number, Number): String;
+}  // namespace runtime
+
+namespace number {
+  const kToRadixFormatRange: constexpr MessageTemplate
+  generates 'MessageTemplate::kToRadixFormatRange';
+
+  extern macro NaNStringConstant(): String;
+  extern macro ZeroStringConstant(): String;
+  extern macro InfinityStringConstant(): String;
+  extern macro MinusInfinityStringConstant(): String;
+
+  const kAsciiZero: constexpr int32 = 48;        // '0' (ascii)
+  const kAsciiLowerCaseA: constexpr int32 = 97;  // 'a' (ascii)
+
+  const MINUS_V8_INFINITY: constexpr float64 generates '-V8_INFINITY';
+
+  transitioning macro ThisNumberValue(implicit context: Context)(
+      receiver: JSAny, method: constexpr string): Number {
+    return UnsafeCast<Number>(ToThisValue(receiver, kNumber, method));
+  }
+
+  // https://tc39.github.io/ecma262/#sec-number.prototype.tostring
+  transitioning javascript builtin NumberPrototypeToString(
+      js-implicit context: Context, receiver: JSAny)(...arguments): String {
+    // 1. Let x be ? thisNumberValue(this value).
+    const x = ThisNumberValue(receiver, 'Number.prototype.toString');
+
+    // 2. If radix is not present, let radixNumber be 10.
+    // 3. Else if radix is undefined, let radixNumber be 10.
+    // 4. Else, let radixNumber be ? ToInteger(radix).
+    const radix: JSAny = arguments[0];
+    const radixNumber: Number = radix == Undefined ?
+        10 :
+        ToInteger_Inline(context, radix, kTruncateMinusZero);
+
+    // 5. If radixNumber < 2 or radixNumber > 36, throw a RangeError exception.
+    if (radixNumber < 2 || radixNumber > 36) {
+      ThrowRangeError(kToRadixFormatRange);
+    }
+
+    // 6. If radixNumber = 10, return ! ToString(x).
+    if (radixNumber == 10) {
+      return NumberToString(x);
+    }
+
+    // 7. Return the String representation of this Number
+    //    value using the radix specified by radixNumber.
+
+    // Fast case where the result is a one character string.
+    if (TaggedIsPositiveSmi(x) && x < radixNumber) {
+      let charCode = Convert<int32>(UnsafeCast<Smi>(x));
+      if (charCode < 10) {
+        charCode += kAsciiZero;
+      } else {
+        charCode = charCode - 10 + kAsciiLowerCaseA;
+      }
+      return StringFromSingleCharCode(charCode);
+    }
+
+    if (x == -0) {
+      return ZeroStringConstant();
+    } else if (NumberIsNaN(x)) {
+      return NaNStringConstant();
+    } else if (x == V8_INFINITY) {
+      return InfinityStringConstant();
+    } else if (x == MINUS_V8_INFINITY) {
+      return MinusInfinityStringConstant();
+    }
+
+    return runtime::DoubleToStringWithRadix(x, radixNumber);
+  }
+}

src/codegen/code-stub-assembler.h

@@ -93,6 +93,7 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(GlobalPropertyCellMap, global_property_cell_map, PropertyCellMap)          \
   V(has_instance_symbol, has_instance_symbol, HasInstanceSymbol)               \
   V(HeapNumberMap, heap_number_map, HeapNumberMap)                             \
+  V(Infinity_string, Infinity_string, InfinityString)                          \
   V(is_concat_spreadable_symbol, is_concat_spreadable_symbol,                  \
     IsConcatSpreadableSymbol)                                                  \
   V(iterator_symbol, iterator_symbol, IteratorSymbol)                          \
@@ -101,9 +102,11 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(match_symbol, match_symbol, MatchSymbol)                                   \
   V(megamorphic_symbol, megamorphic_symbol, MegamorphicSymbol)                 \
   V(MetaMap, meta_map, MetaMap)                                                \
+  V(minus_Infinity_string, minus_Infinity_string, MinusInfinityString)         \
   V(MinusZeroValue, minus_zero_value, MinusZero)                               \
   V(name_string, name_string, NameString)                                      \
   V(NanValue, nan_value, Nan)                                                  \
+  V(NaN_string, NaN_string, NaNString)                                         \
   V(next_string, next_string, NextString)                                      \
   V(NoClosuresCellMap, no_closures_cell_map, NoClosuresCellMap)                \
   V(null_to_string, null_to_string, NullToString)                              \
@@ -149,7 +152,8 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(undefined_to_string, undefined_to_string, UndefinedToString)               \
   V(UndefinedValue, undefined_value, Undefined)                                \
   V(uninitialized_symbol, uninitialized_symbol, UninitializedSymbol)           \
-  V(WeakFixedArrayMap, weak_fixed_array_map, WeakFixedArrayMap)
+  V(WeakFixedArrayMap, weak_fixed_array_map, WeakFixedArrayMap)                \
+  V(zero_string, zero_string, ZeroString)
 
 #define HEAP_IMMOVABLE_OBJECT_LIST(V)   \
   HEAP_MUTABLE_IMMOVABLE_OBJECT_LIST(V) \

src/runtime/runtime-internal.cc

@@ -601,5 +601,18 @@ RUNTIME_FUNCTION(Runtime_GetInitializerFunction) {
   Handle<Object> initializer = JSReceiver::GetDataProperty(constructor, key);
   return *initializer;
 }
+
+RUNTIME_FUNCTION(Runtime_DoubleToStringWithRadix) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_DOUBLE_ARG_CHECKED(number, 0);
+  CONVERT_INT32_ARG_CHECKED(radix, 1);
+
+  char* const str = DoubleToRadixCString(number, radix);
+  Handle<String> result = isolate->factory()->NewStringFromAsciiChecked(str);
+  DeleteArray(str);
+  return *result;
+}
+
 }  // namespace internal
 }  // namespace v8

src/runtime/runtime.h

@@ -210,6 +210,7 @@ namespace internal {
   F(AllowDynamicFunction, 1, 1)                      \
   I(CreateAsyncFromSyncIterator, 1, 1)               \
   F(CreateListFromArrayLike, 1, 1)                   \
+  F(DoubleToStringWithRadix, 2, 1)                   \
   F(FatalProcessOutOfMemoryInAllocateRaw, 0, 1)      \
   F(FatalProcessOutOfMemoryInvalidArrayLength, 0, 1) \
   F(GetAndResetRuntimeCallStats, -1 /* <= 2 */, 1)   \